A protocol for the C–H activation/iodination of benzoic acids catalyzed by a simple iridium complex has been developed. The method described in this paper allows the ortho-selective iodination of a variety of benzoic acids under extraordinarily mild conditions in the absence of any additive or base in 1,1,1,3,3,3-hexafluoroisopropanol as the solvent. The iridium catalyst used tolerates air and moisture, and selectively gives ortho-iodobenzoic acids with high conversions. Mechanistic investigations revealed that an Ir­(III)/Ir­(V) catalytic cycle operates, and that the unique properties of HFIP enables the C–H iodination using the carboxylic moiety as a directing group.

Remarkably simple IrIII catalysts enable the isomerization of primary and sec‐allylic alcohols under very mild reaction conditions. X‐ray absorption spectroscopy (XAS) and mass spectrometry (MS) studies indicate that the catalysts, with the general formula [Cp*IrIII], require a halide ligand for catalytic activity, but no additives or additional ligands are needed.

-Diiodo-5,5-dimethylcyclohexane-1,3-dione is reported as a new electrophilic iodinating agent that selectively iodinates electron-rich aromatics. In contrast to other common electrophilic iodinating reagents, its mild nature allows it to be used for the selective synthesis of a-iodinated carbonyl compounds from allylic alcohols through a 1,3-hydrogen shift/iodination process catalyzed by iridium(III) complexes.Halogenated organic compounds are ubiquitous, not only as natural products, 1 but also as synthetic compounds, and they have applications in medicinal chemistry, 2 agrochemistry, 3 and materials science. 4 The halogen functional group is very versatile.

Antonio Bermejo Gómez, [a, b] Elis Erbing, [a, b] María Batuecas, [a] Ana Vµzquez-Romero, [a] and BelØn Martín-Matute* [a, b] Abstract: a-Brominated ketones and aldehydes, with two adjacent electrophilic carbon atoms, are highly valuable synthetic intermediates in organic synthesis, however, their synthesis from unsymmetrical ketones is very challenging, and current methods suffer from low selectivity. We present a new, reliable, and efficient method for the synthesis of abromocarbonyl compounds in excellent yields and with excellent selectivities. Starting from allylic alcohols as the carbonyl precursors, the combination of a 1,3-hydrogen shift catalyzed by iridium(III) with an electrophilic bromination gives a-bromoketones and aldehydes in good to excellent yields. The selectivity of the process is determined by the structure of the starting allylic alcohol; thus, a-bromoketones formally derived from unsymmetrical ketones can be synthesized in a straightforward and selective manner.

Iridium-Catalyzed Isomerization/Bromination of Allylic Alcohols: Synthesis of -Bromocarbonyl Compounds. -A novel method for the synthesis of -bromoketones as single constitutional isomers is developed using an Ir-catalyzed bromination/isomerization sequence starting from allylic alcohols. -(GOMEZ, A. B.; ERBING, E.; BATUECAS, M.; VAZQUEZ-ROMERO, A.; MARTIN-MATUTE*, B.; Chem. -Eur. J. 20 (2014) 34, 10703-10709, http://dx.doi.org/10.1002/chem.201402350 ; Dep. Org. Chem., Arrhenius Lab., Univ. Stockholm, S-106 91 Stockholm, Swed.; Eng.) -Mais 08-052